Hm, that doesn't make sense. The random disconnects can be explained, depending on what you use to wallwalk. GMs shouldn't randomly kill you and you also shouldn't get muted. If anything, you should receive a warning, a short ban, the length increasing up until a permaban if you keep breaking the rules. Thing is, if you're doing this all legit (Levitate), they shouldn't find out unless you flaunt the fact that you're doing these things (e.g. saying that you're in places you're not meant to be in chat channels and someone reports you). Going to Hyjal and getting No Man's Land can also send messages to GMs apparently, so if you've done that they could be looking for you. Either way, you shouldn't have anything to worry about until you get a formal warning.